Rocker arm assembly

Abstract

A bearing support member and bearings form a subassembly that can be inserted, in the direction of the axis of the bearings, into a bore of a rocker arm. A support stud can then be passed through an aperture in the rocker arm and a bore in the bearing support member so as to engage the rocker arm and maintain alignment of the rocker arm and bearings. Also disclosed are an inner sleeve and particular configuration of the bearing support member to facilitate manufacture of the bearing support member by powdered metal forming.

Having described the invention, what is claimed is: 
     
       1. A rocker arm assembly comprising: a bearing support member adapted for mounting on a support stud;   two annular bearings having a common axis, supported and retained on the bearing support member, the circumference of the bearings defining a cylindrical envelope perpendicular to the support stud and enclosing the bearing support member;   a rocker arm having a bore larger than the diameter of the cylindrical envelope and having an aperture for receiving the support stud, the bearings forming a clearance fit within the bore such that the rocker arm may be pivoted on the bearings about the axis of the bearing support member; and   retaining means on the rocker arm engageable with the support stud for limiting movement of the rocker arm away from the support stud and for limiting axial movement of the rocker arm relative to the bearings.   
     
     
       2. The rocker arm assembly of claim 1, wherein the retaining means comprises surfaces on the rocker arm adjacent to the aperture of the rocker arm engageable with surfaces on the support stud. 
     
     
       3. The rocker arm assembly of claim 1, wherein the bore of the rocker arm is sufficiently large such that the bearing support member can be easily inserted into the bore and such that the bearings form a loose fit with the rocker arm. 
     
     
       4. The rocker arm assembly of claim 1, wherein the bearing support member has shoulders engaging the bearings and limiting movement of the bearings toward the support stud. 
     
     
       5. The rocker arm assembly of claim 1, wherein the bearings include an inner sleeve providing an inner race, an outer sleeve providing an outer race, and a plurality of rollers therebetween. 
     
     
       6. The rocker arm assembly of claim 5, wherein the inner sleeve is retained on the bearing support member by an interference fit. 
     
     
       7. The rocker arm assembly of claim 5, wherein the bearing support member has a noncylindrical surface over which the inner sleeves of the bearings are mounted. 
     
     
       8. The rocker arm assembly of claim 7, wherein the noncylindrical surface of the bearing support member, in cross-section, has a first arcuate portion extending less than 180 degrees and a smaller second arcuate portion of the same radius opposite the first arcuate portion and a second smaller arcuate portion opposite the first arcuate portion, both arcuate portions engaging the inner sleeve, the arcuate portions being separated by tool reliefs that do not engage the bearings. 
     
     
       9. The rocker arm assembly of claim 8, wherein the tool reliefs are symmetrical and are formed by angled portions angled at approximately 45 degrees from a plane of symmetry and by flat portions substantially perpendicular to the plane of symmetry. 
     
     
       10. A method of assembling a rocker arm assembly, the method comprising the steps of: providing a bearing support member having a first bore to receive a support stud;   mounting bearings on the bearing support member, on a common axis perpendicular to the first bore and on opposite sides of the first bore, to provide a bearing subassembly;   providing a rocker arm having a second bore to accommodate the bearing subassembly and having an aperture to accommodate the support stud;   inserting the bearing subassembly axially into the second bore to a position in which the bearings form clearance fit with the rocker arm on opposite sides of the aperture of the rocker arm; and   inserting the support stud through the aperture of the rocker arm and through the first bore such that movement of the bearing support member and rocker arm away from the support stud is limited by engagement of the rocker arm with the support stud.   
     
     
       11. The method of assembling the rocker arm assembly of claim 10, wherein the step of mounting bearings on the bearing support member includes rigidly mounting an inner sleeve on the bearing support member, the inner sleeve providing an inner race surface for rollers and limiting movement of the rollers axially relative to the axis of the bearings. 
     
     
       12. The method of assembling the rocker arm assembly of claim 11, wherein the step of mounting bearings on the bearing support member includes staking. 
     
     
       13. The method of assembling the rocker arm assembly of claim 11, wherein the bearing support member is made of powdered metal. 
     
     
       14. The method of assembling the rocker arm assembly of claim 10, wherein the bearing support member is made of powdered metal formed by dies moved in the direction of the axis of the first bore. 
     
     
       15. A rocker arm bearing assembly for use with a rocker arm having a first bore, the bearing assembly comprising: a bearing support member having a second bore;   two annular inner sleeves having a common axis and being rigidly mounted on the bearing support member, each of the inner sleeves having a radially outwardly extending first flange;   two annular outer sleeves coaxial to and radially outward of the inner sleeves, each of the outer sleeves having a radially inwardly extending second flange engageable with the bearing support member such that movement of the outer sleeve toward the second bore is restricted, the circumference of the outer sleeve defining a cylindrical envelope perpendicular to the second bore and enclosing the support member, the cylindrical envelope having a diameter smaller than the first bore such that a clearance fit is provided; and   a plurality of rollers within the annulus between each inner sleeve and between the first and second flanges, the rollers being retained in the direction of the axis of the sleeves by the first and second flanges.